Tape measures typically consist of a flexible tape resiliently coiled within a housing. The tape is normally printed with incremental measuring marks for measuring distances. In use, the flexible tape is uncoiled and extended from the housing and placed on a surface to be measured. Distances can then be marked with a separate marking tool directly onto the surface.
Numerous devices have been developed for incorporating marking tools inside the tape housing to facilitate marking with one hand. For instance, Doak et al. (U.S. Pat. No. 4,760,648; issued Aug. 2, 1988) discloses a marking device that is attached to the exterior of a tape measure housing. The marking device has a marking member that is moved downwardly into contact with the article to be measured. A prong projects from the side of the marking device to indicate where the mark will be made. A disadvantage of the Doak et al. ('648) device is that the marking device protrudes from the side of the tape measure and interferes with making marks near walls and other structures associated with the surface to be marked. In addition, the marker and indicator prong tend to get caught on a user's clothing, and the indicator prong can be easily bent out of alignment with the marker. Finally, a liquid-based marking tool would tend to quickly dry out in the Doak et al. ('648) device because of being directly and continuously exposed to the atmosphere.
Another type of measuring tape is disclosed in Samson (U.S. Pat. No. 4,729,171; issued Mar. 8, 1988). The Samson ('171) device utilizes a pair of markers mounted inside the housing at the forward and rearward ends thereof. The markers retract through openings in the housing and are manually extended by buttons partially protruding from the sidewalls of the housing. One drawback to this measuring tape is the exposure of the marking tools to the atmosphere through the openings in the housing. Dirt and other foreign material can easily enter the housing through the openings and interfere with the proper functioning of the marking tools and the tape measure. The buttons are controlled from the side of the device which make it difficult to make a mark in tight quarters.
Elliott (U.S. Pat. No. 4,439,927; issued Apr. 3, 1984) discloses a tape measure having a marker, a scriber, and a braking mechanism. The braking mechanism is automatically activated when the marker or the scriber is positioned for marking the object being measured. This device has the disadvantage of tabs projecting from the sidewall that can interfere with marking near walls or other structural members associated with the marking surface. In addition, the marker is positioned on only one side of the tape, thus limiting the choices of placing the mark in a desired location. Finally, although the marker is withdrawn within the housing, it is still exposed to the outside air and foreign material through the opening in the bottom of the housing.
Other patents which reveal various measuring devices include: Pas (U.S. Pat. No. 1,470,470; issued Oct. 9, 1923); Raphael (U.S. Pat. No. 1,613,676; issued Jan. 11, 1927); Mills (U.S. Pat. No. 2,624,120; issued Jan. 6, 1953); Nelson (U.S. Pat. No. 2,759,696; issued Aug. 21, 1956); Bateman (U.S. Pat. No. 2,847,765; issued Aug. 19, 1958); Cederholm (U.S. Pat. No. 3,045,788; issued Jul. 24, 1962); Keene (U.S. Pat. No. 3,063,157; issued Nov. 13, 1962); Taylor (U.S. Pat. No. 3,100,941; issued Aug. 20, 1963); Duncan et al. (U.S. Pat. No. 3,157,950; issued Nov. 24, 1964); Beckett (U.S. Pat. No. 3,262,211; issued Jul. 26, 1966); Chamaberlain et al. (U.S. Pat. No. 3,336,678; issued Aug. 22, 1967); King (U.S. Pat. No. 3,731,389; issued May 8, 1973); Freed (U.S. Pat. No. 3,802,083; issued Apr. 9, 1974); Taylor (U.S. Pat. No. 4,015,337; issued Apr. 5, 1977); Yamamoto (U.S. Pat. No. 4,542,589; issued Sep. 24, 1985); and Pentecost (U.S. Pat. No. 4,630,376; issued Dec. 23, 1986).
The inventor believes the known prior art taken alone or in combination neither anticipate nor render obvious the present invention. These citations do not constitute an admission that such disclosures are relevant or material to the present claims. Rather, these citations relate only to the general field of the disclosure and are cited as constituting the closest art of which the inventor is aware.